Black Death in Eastern Oregon? Local plague risk low, but health officials encourage preventative measures

By on Friday, February 16th, 2024 in More Top Stories Northeastern Oregon News

UNION COUNTY – A recent case of a Bend resident diagnosed with bubonic plague has made national news, with the likely source of infection traced back to their symptomatic pet cat.

While the health officials say most humans face a relatively low risk, the Center of Human Development (CHD) in Union County and the Oregon Department of Fish & Wildlife both emphasize the importance of preventive measures, considering the historical prevalence of plague in certain regions.

According to CHD, in the United States, the majority of human plague cases occur in specific areas, including Northern New Mexico, northern Arizona, southern Colorado, California, southern Oregon, and far western Nevada. Oregon has reported only 19 cases between 1970 and 2020, with a low number of deaths (14 deaths in 496 cases during the same period).

Of course, the most well known outbreak of the plague occurred in the 14th century. It caused the Black Death — the pandemic that may have killed 30% to 50% of the population in parts of Europe, with an estimated death toll of at least 50 million. It’s well known that it  spreads through rodents and the fleas that bite them.

So, how did the plague arrive in Oregon?

“It was most likely brought to western United States in the 1890’s from ships coming from Asia that had rats with the disease,” said Dr. Colin Gillin, State Wildlife Veterinarian with the ODFW. “We now see it in most western states and residing in small mammal populations. Human infections are rare.”

Dr. Gillin says he’s seen cases in mammals such as prairie dogs and even deer become infected with the disease in Oregon, but the majority of cases are still found to be in rats and mice. 

“There’s some species of rodents that tend to be reservoirs for it. It doesn’t kill them,” says Dr. Gillin. “It may make them minorly sick or not sick at all, but they replicate the bacteria and just maintain it.”

Dr. Gillin says another mammal that has tested positive for the plague routinely in Oregon are cats that eat infected rodents, such as the case in Bend.

“When there’s an outbreak where you have a lot of plague showing up in the environment, you’ll see the effect on bobcats and even cougars will be high. They’ll be sick. They’ll have high death rates.”

Dr. Gillin says one way to suspect a plague outbreak in wildlife is mass die-offs of animals, which the ODFW keeps an eye out for.

“The plague is out there, but in real low-levels,” says Dr. Gillin. “It’s considered what we would call endemic in North America. It’s here. It’s in the fabric of our ecosystems and our wildlife. It’s not going anywhere. That’s because of these permanent infections in reservoir species like rodents.

If anyone is concerned about the plague, they are encouraged to take the following preventive measures:

Rodent Habitat Reduction: Minimize rodent habitat around homes, workplaces, and recreational areas by removing brush, rock piles, junk, cluttered firewood, and potential rodent food supplies, such as pet and wild animal food. Ensure that homes and outbuildings are rodent-proof.

Safe Handling of Animals: If handling or skinning potentially infected animals, wear gloves to prevent direct contact between the skin and plague bacteria. For questions about the disposal of dead animals, residents can contact their local health department.

Repellent Use: When engaging in outdoor activities like camping, hiking, or working, use repellents to avoid exposure to rodent fleas. Products containing DEET can be applied to both skin and clothing, while those with permethrin can be applied to clothing (always follow instructions on the label).

Pet Protection: Keep fleas off pets by applying flea control products. Pets that roam freely are more likely to come into contact with plague-infected animals or fleas, potentially bringing them into homes. If a pet becomes sick, seek prompt care from a veterinarian.

Limit Pet Access: In endemic areas, avoid allowing dogs or cats that roam freely to sleep on beds, reducing the risk of bringing potential infections into the household.